Commit 037b91ec authored by Valentin Caron's avatar Valentin Caron Committed by Greg Kroah-Hartman
Browse files

serial: stm32: fix software flow control transfer 



x_char is ignored by stm32_usart_start_tx() when xmit buffer is empty.

Fix start_tx condition to allow x_char to be sent.

Fixes: 48a6092f ("serial: stm32-usart: Add STM32 USART Driver")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: default avatarErwan Le Ray <erwan.leray@foss.st.com>
Signed-off-by: default avatarValentin Caron <valentin.caron@foss.st.com>
Link: https://lore.kernel.org/r/20220111164441.6178-3-valentin.caron@foss.st.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d3d079bd

drivers/tty/serial/stm32-usart.c

+1 −1
Original line number Diff line number Diff line
@@ -742,7 +742,7 @@ static void stm32_usart_start_tx(struct uart_port *port) 
	struct serial_rs485 *rs485conf = &port->rs485;

	struct circ_buf *xmit = &port->state->xmit;



	if (uart_circ_empty(xmit))

	if (uart_circ_empty(xmit) && !port->x_char)

		return;



	if (rs485conf->flags & SER_RS485_ENABLED) {